18 inch labhorn design.

[davygrvy]

Actually, it does become distorted then or are meaning it happens lower? If not the 1 atmosphere limit, then what aspect of throat distortion are you referring to?

I'd sure like to hear a subhorn that can approach that limit

 

[CLS]

...You have a fold for this?

Here you are:

And it's used indoor, close to the side walls. It's very big already and the space seems too small for it. So no stacking.

It's measured very flat down to high 20 ~ low 30, just as the sim.

Pipe organ from them is just shakingly magnificent. 😎

 

[stewin]

cowann made a version of 18lab in his website and removed the plans a few years ago . you can pm him for more ideas.

 

[stewin]

cowann made a version of 18lab in his website and removed the plans a few years ago . you can pm him for more ideas.

😎😕😎

 

[stewin]

hi all any photos for the concept

 

[$$Maan]

I like that you come back after so long
I've been sitting here just waiting
Took me a couple of month do do this post

I still wonder how CLS got that area to fit with the drawing.
Looks like a nice horn though

 

[djmip]

lab 18

I built a lab18 to try it out planning on building 4 in total although it's on the back burner at the moment I got the plans from amino I think his user name is on speakerplans tried it out with just 1 bin in a corner loaded with a void v18 and it was very impressive considering was only one . Had people phoning from shops about a mile away other side of housing estate asking if the noise was coming from me. lol . if u want the plans reply to this and I will check with my mate make sure it's OK but sure it will be. It's 3/1 compression I think 🙂 . it's bloody heavy tho at 4ft height and 4ft deep and 600 wide

 

[djmip]

sorry new to here can't seem to upload a pic of it . here are links hope they work
https://m.facebook.com/photo.php?fb...52890348625510.1073741827.661615509&source=56

https://m.facebook.com/photo.php?fb....10152088964800510.908001.661615509&source=56

 

[stewin]

hi dj pls post plans in pdf format .

dbh18 is a form of lab 18sub i tend to think so

 

[djmip]

http://photo.qip.ru/photo/amanosempai/135186807/138894491.jpg

 

[zettairyouiki]

Throat distortion comes from the opposite end of the cycle of doubling atmospheric pressure which is a vacuum. You can't get less than a vacuum, but you can still increase pressure, thus the distortion. Off-hand, I think it's 194dB.

I know that was a problem with the EV MT-4 where they put four DH-3 HF compression drivers through a single horn. It was a great space saver, but they bumped the physical limit where water both boils and freezes at the same time.

Right, 194db is a the limit where the sound is brickwall clipped by physical vacuum.

As intense as SPL is in horn throats, I don't think EV got anywhere near that point. That's an incredible amount of energy. I do believe it's possible that the rarefaction could reach levels where the water vapor in the air would begin oscillating between liquid and gaseous phases due to temperature and pressure fluctuations. It certainly doesn't take 194db to do that, but I don't know exactly how much of a problem this would present or at what SPL it might happen. (Not the triple point, btw).

The real issue is that speakers operate under the assumption that air behaves as a linear spring. That the restorative force is proportional to displacement. At normal levels, this is for all intents and purposes true. But as you get to higher pressures the air starts to compress non-linearly. Nonlinear behavior starts to introduce distortion products.

That's the real problem EV was facing. Water vapor aside, it turns out that when you cram a bunch of compression drivers into a tiny manifold, air itself simply fails to behave nicely at those throat pressures, and it was audible in the distortion.